locateEvents function

Locate Events on the Current Plot

Locate events on the current plot (using the locator

function).

locateEvents (EID, n = 512, type = "p", ...)

Arguments

• EID: vector of event IDs (optional).
• n: maximum number of events to locate.
• type: one of "n", "p", "l", or "o". If "p" or "o", then the points are plotted; if "l" or "o", then the points are joined by lines.
• ...: additional par parameters for the locator function.

Details

This function allows its user to define events with mouse clicks on the current plot via the locator function. The arguments n and type are the usual parameters of the locator function. If EID is not missing, then n = length(EID).

On exit from locator, suppose the user defined m

events. If EID was missing, then the output data frame will contain m events. However, if EID exists, then the output data frame will contain length(EID) events, and both X and Y will be NA for events EID[(m+1):n]. The na.omit function can remove rows with NAs.

Returns

EventData with columns EID, X, and Y, and projection attribute equal to the map's projection. The function does not set the zone attribute.

Author(s)

Nicholas M. Boers, Staff Software Engineer

Jobber, Edmonton AB

Last modified Rd: 2007-06-06

See Also

addPoints, combineEvents, convDP, EventData , findCells, findPolys, plotPoints.

Examples

#--- define five events on the current plot, numbering them 10 to 14
## Not run: events <- locateEvents(EID = 10:14)